Mobile LiIon battery charger

just curious

Newly Enlightened
Joined
Jan 28, 2012
Messages
1
so, is it possible to make a mobile charger from some LiIon battery with greater cap, like ~3000mAh (could be lap-top battery or standard e.g. 18650), to charge smaller LiIon 3,7V cylindric batteries, like ~500mAh?
plz answer, because this will mean a lot to many ppl.
 

Wrend

Enlightened
Joined
Oct 14, 2010
Messages
646
Location
United States, IL
Yes, of course. The main thing would be to find or make the right charge controller that used the desired input and output voltages.

Possibly a simple solution would be to find a 12VDC input car charger take it apart and hook that up to 4S LiFePO4 cells.
 

TEEJ

Flashaholic
Joined
Jan 12, 2012
Messages
7,490
Location
NJ
You would be limited to the DIFFERENCE between them, as they would tend to equalize.
 

Wrend

Enlightened
Joined
Oct 14, 2010
Messages
646
Location
United States, IL
That's just if you connected them in parallel directly and they were the same chemistry type and cell count in series. They would then balance at the same voltage level. I wouldn't really recommend doing that though, unless you know specifically what you're doing as the rate wouldn't be controlled.
 

AnAppleSnail

Flashlight Enthusiast
Joined
Aug 21, 2009
Messages
4,200
Location
South Hill, VA
so, is it possible to make a mobile charger from some LiIon battery with greater cap, like ~3000mAh (could be lap-top battery or standard e.g. 18650), to charge smaller LiIon 3,7V cylindric batteries, like ~500mAh?
plz answer, because this will mean a lot to many ppl.
I highly suggest that you use the charging battery as the power input to a Li-Ion battery charger. There are many that are meant to run off 5V. I cannot recommend just damming cells in parallel to charge one, as this can be overly exciting.

Why will this mean a lot to many people? E-cigs?
 
Top